Learn the Nine Essential Parts of Eyeglasses - American ... Read on to prepare yourself for your next trip to the optician. Here are the nine main parts of eyeglasses: 1. Rims. The rims lend form and character to your eyeglasses—they also provide function by holding the lenses in place. 2. End pieces. The end pieces are the small parts on the frame that extend outward and connect the lenses to the ...